Creating Permanent Complete Heart Block by Indirect Cauterization Without Atriotomy

We created permanent complete heart block (CHB) in 11 dogs without atriotomy by means of indirect cauterization of the atrioventricular (A-V) bundle with a partially insulated wire placed through a small puncture in the atrial wall and guided by palpation. In six acute studies and five chronic studies, all dogs exhibited permanent CHB. To test the block, isoproterenol increased both atrial and ventricular rates 200%-400% without affecting the block. Atropine had no effect on ventricular rate or block.